A model of effective literary adaptation, the first screen version of William Golding's 1955 novel (even then recognised as a modern classic) was also the cinema debut of one of Britain's most innovative and adventurous theatre directors. Characteristically for Peter Brook, the film was developed unconventionally via a series of workshops based on the original novel, without going through the usual screenplay stage.

He also opted for an entirely non-professional cast, with impressively convincing results. Though performances are far from flawless, the more technically polished efforts of drama school pupils might have undermined Golding's key theme: that civilisation is merely a paper-thin façade which, when removed, leads to chaos.

In this case, civilisation effectively ends when a planeload of schoolboys crashes on an unidentified desert island, depriving them of adult supervision. Initially, this seems idyllic (the ultimate children's fantasy, in many ways), but things rapidly turn nasty as the boys' behaviour becomes more aggressive and tribal, with 'outsiders' like Piggy (overweight, short-sighted) and Simon (loner, free-thinker) quickly isolated and condemned by the rest. Ralph represents the voice of conscience and sanity, but he's usually forced to be a passive observer, afraid to speak out because of the sheer weight of numbers potentially stacked against him. It's far easier to side with Jack, the strongest and most decisive of the boys, even if this means abandoning the moral principles that would have been drilled into these privileged children from birth.

When Brook made the film, he deliberately tried to duplicate the conditions depicted in the novel as much as was feasible (given the need for adults to actually shoot the film). He transported his young cast to the island of Vieques, near Puerto Rico, and made them live in an abandoned pineapple cannery that had been crudely kitted out with the most basic facilities. Life magazine journalist Robert Wallace visited them there and observed one of them amusing himself by feeding live lizards into the blades of a rotating fan. Wallace commented: "One could almost hear William Golding, 4,000 miles away in England, chuckling into his beard."

The novel was filmed again in 1990 by the British director Harry Hook, this time in colour and with a cast of American professionals. Perhaps inevitably, it could only muster a fraction of the power of Brook's version, whose innate understanding of the message of Golding's novel permeates every frame.